Excerpt from 'Excerpt from 'Hayat Al-Qulub, Vol. 1':
According to correct reports Muhammad ibn Muslim asked Imam Muhammad al-Baqir the period Ya‘qub remained alive after he was reunited with Yusuf in Egypt.
'Two years,' he replied.
'Who was the hujjah (Proof) of Allah on Earth? Ya‘qub or Yusuf?'
Ya‘qub was the proof of Allah. Yusuf was associated with the throne. When Ya‘qub passed from this world, his mortal remains were placed in a coffin and transported to Syria. He was buried in the Jerusalem. After the demise of Ya‘qub, Yusuf was conferred the position of hujjahullah (Proof of Allah).'
The narrator asked Imam if Yusuf was a Prophet and a Messenger. Imam said, 'Yes, it seems you have not heard that the Almighty says in Qur’an:'
”And a believing man of the Pharaoh’s people who hid his faith said, What! Will you slay a man because he says: My Lord is Allah, and indeed he has brought to you clear arguments from your Lord? And if he be a liar, on him will be his lie, and if he be truthful, there will befall you some of that which he threatens you (with); surely Allah does not guide him who is extravagant, a liar: O my people! Yours is the kingdom this day, being masters in the land, but who will help us against the punishment of Allah if it come to us?
The Pharaoh said, I do not show you aught but that which I see (myself), and I do not make you follow any but the right way.
And he who believed said, O my people! Surely I fear for you the like of what befell the parties: The like of what befell the people of Nuh and ‘Ad and Thamud and those after them, and Allah does not desire injustice for (His) servants; And, O my people! I fear for you the day of calling out, The day on which you will turn back retreating; there shall be no saviour for you from Allah, and whomsoever Allah causes to err, there is no guide for him: And certainly Yusuf came to you before with clear arguments, but you ever remained in doubt as to what he brought; until when he died, you said, Allah will never raise an apostle after him.”